Safety device for electric trains.



' PATENTED JULY v, 1908. A.H.DAUS.

SAFETY DEVICE FOR ELECTRIC TRAINS.

APPLICATION F ILED DEG.30,1907. v

2 SHEETS-SHEET 1.

wa s

cfrzvenz'bz': ufdoz vh ii Baa/s No. 892,713. PATENTED JULY '7, 1908. A. H. DAUS.

SAFETY DEVICE FOR ELECTRIC TRAINS.

APPLICATION FILED DEO.30,1907.

2 SHEETS-SHEET 2.

' 2 @WM/M ADOLPH H. DAUS, OF CHICAGO, ILLINOIS.

SAFETY DEVICE non ELECTBEG TRAINS.

No. sea 71s.

To all whom it mag concern:

Be it known that l, Anonrn H. Dans, citizen o'f'the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful lmprovernent in Safety Devices for Electric Trains, of which the following is a-full, clear,

concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

It is an object of my'invention to provide improvements in interlocking safety devices on cars electrically driven to prevent accidents resulting from the. brakes being in a condition to revent control of the train.

My invention isparticularly applicable to systems of train operation in which one or' more cars of the train are equipped with electriomotors for driving such cars and these motors are jointly controlled from a master controller located as desired on the train. In common practice several of the cars of the train may be provided with such master controllers and whether there is a motor on one car only or there are motors on several of the cars, the control exercised from each of the controllers governs all of the motors. in systems of this character air brakes are usually employed to stop the train, and my invention specifically consists in means associated with the controlling valves of such air brake system by which if such valves are not properly set to err'nitjhe operation of the brakes the contro exercised by the controllers is interrupted and can only be restored'by properly setting such valves.

In systems of control of the class above described, it is usual to run controlling leads through the train and to connect these leads' to the several controllers, such leads being connected to the electromagnetic mechanism employed to operate the motor, or in case several motors are in operation on the train a' plurality of such electromagnetic mechanisms are thus connected. An air-controlling valve is usually associated with each controller, and my invention in its simplest form consists in switching means associated with each of such valves for. interrupting the main operatin circuit of the associated controller if the va ve is in a osition to prevent the operation of the brakes and for opening the operating circuit governed by this controller at another point it a second switch is in a osition to permit the operation of the bralies from that location on the train. In connec- Specification of Letters Patent.

Application filed December 30, 1967.

Patented an 7, recs.

Serial No. wane.

tion with the system herein disclosed this is accomplished by operating the tripping circuit of the main circuit breaker when avalve located at a positionon the train other than that of the controller-used at that time in o crating the train is in a position to permit t e operation of the brakes. This circuit breaker is so connected with the motors andcontrollers that such controllers are rendered inoperative when the circuit breaker is in'release oropen position.

My invention further consists in actuating this circuit breaker tripping mechanism when the air pressure in the braking system is in suflicient to o erate the brakes.

' The severe drawings illustrating my invention are as follows:

Figure 1 shows in diagrammatic view my system as applied to a train of two cars, and shows the associated operating mechanism and brake-controlling mechanism used on each end of each car. Figs. 2 and 3 are detailed views oi a preferable form of construction of switch to be operated by one of the air valves to be described. Fig. 4 is a detailed view of the air cylinder for o crating a safety switch, as will also be descri ed.

Referring to Fig; l, C, C C and C represent the electric controllers located one on each end of each of the cars of the-train, the dividing line between these cars being indicated by the dotted line x-y. Associated with each. controller is a brake-operating mechanism designated by V, V V and V Since the several controllers are identical in their construction and operation, it is only necessary to describe one of them, as C, in which the several contacts, as 4, 5, 1, 3, 10, 8, 9 and ll are adapted to make contact with the contact blocks 0, c to 0 according to the operation of the controller 0. These several contacts and contact blocks are connected as follows: Contacts 5 and 1 are connected together and to contact point 19 of switch 8 by wire 29. Contact points 3, 10, 9 and ll are connected together. Contact point 8 is connected by wire 28 with one terminal of the magnetic blow-out coil .33. Contact point i is connected to contact 14 of switch s and to train wire 6 by wire 32. Three train wires, 2, 6 and 7, are shown extending from one end of the train to the other and connected from one car to the other by jumper connectors, and these wires are used for the purpose of controlling the motor mechanism on any one or all of the cars from any one of the controllers on the train. 1 have herein shown only sufficient of these train wires to illustrate the operation of my safety system, and it will be understood that in practice for perfectly controlling the motor mechanism more of these train wires are made use of. The magnetic blow-out coil 33 is connected by its other terminal through wire 27, through a fuse as indicated, to the pivotal point of switch 8, which serves to cut the controller G into circuit or out of. circuit, as desired. The wire 27 also connects to the pivotal point of switch 8 which is designed to occupy a central or neutral position when not held in one of its operative positions by the motorman. This switch s is adapted to make contact with the contact points 13 and 14 connected respectively by wires 31 and 32 to the train wires 7 and 6 and operates'in a manner and for a purpose to be described later; The contact 12 of switch 8 is connected by wire 26 and wire 25 with the trolley T by which power is supplied to the controller 0 to operate the motor" controlling mechanism. A third rail shoe 36 is shown connected with the trolley T by wire 24, indicating the-adaptability of my system to either third rail systems or overhead trolley systems.

The main circuit through the motor mechanism of the car may be traced as follows: trolley '1, wire 25, contact 52, switch 51, wire 53, contact 54 of a circuit breaker 55, to and through an overload solenoid coil 48, wire 47, armature winding M, field winding f, switch 46, contact 45, resistance r, armature winding M of a second motor, field winding f of such motor to ground.

The circuit breaker 55- is adapted to be closed by solenoid 38 acting upon a core 44 suitably secured to. the switching arm of such solenoid, a spring 56 is provided to maintain the arm 55 normally in position shown in Fig.

1. A latch 58 is associated with the circuit.

breaker 55 to hold the switch lever in contact with contact point 54 when such circuit breaker is closed, this action of the latch 58 being due to the s ring 57, which moves the latch around on t e pivot 59 to engage the switch lever, as is apparent from the drawing. Means are provided for releasing the circuit breaker, consisting in either one of two coils, 48 or 49, adapted to act upon the core 50'and thus to move the latch 58 out of engagement with the switch lever 55 and permit the spring 56 to open circuit between the contact 54 and such switch lever. The solenoid winding 38 is connected from train wire 7 through a suitable fuse by wire 37, wire 39 and resistance r to ground. The coil 48 is in series with the motor armatures at all times and constitutes .an overload release for tripping the circuit breaker when the current in the motor armature becomes excessive. The coil 49 is connected between the train wire 6 through a suitable fuse as indicated to ground.

teams The air brake controlling system shown in connection with this invention consists in a motor M adapted to drive an air urnp P connected to an air tank R and suppiy pipe p for furnishin air as required to operate the braking mec anism. This pipe 1) extends throughout the train, as does a second pipe p known as the train pipe. Connections are made from the pipes p and p at each position of control b pipes 19 and p respectively through va ves v and o to a controlling valve of a type well known in the art. A third pipe 12* known as the exhaust pipe is also connected to this 0 erating valve. A

.valve v is connected wit the train pipe p and there are also connected to this valve an air tank R and o crating cylinder 23 for operating the bra res. The valve e is adapted to be operated in such a manner that when the pressure in the pipe p reaches a certain amount this valve 1s operated to 0 en a assageway between the pipe 1) and t e tan R This condition is maintained as long as the pressure in the pipe 19 is maintained, and when the air is permitted to escape from the pi e p and the pressure is thereby diminishe below a certain predetermined amount, the valve 12 operates to form a passage between the tank It and the cylinder 23, as a result of which the air in the tank R serves to set the brakes in a manner well known. When the ressure in the pipe 12 is again increased to tlie amount required to o erate the valve e connection is again esta lished between the pipe p and the tank R through such valve and an exhaust assage is opened from the cylinder 23 by w ich the brakes are released. The switch 8 mentioned above is associated with the valve 12 in such a manner that when this valve occupies an open position connection is made between contacts 18 and 19 by such switch. It is to be noticed that the handles of the valves 2; and '0 are so proportioned that it is necessary to open the valve o before the valve 12 can be opened, and it is therefore provided by this device that air maybe supplied through the controlling mechanism 12 for operating the brakes before the'motors on the train can be operated, since for this condition the switch 8 must be closed, as will be explained.

In operating my mechanism the mainv switch 51 is first closed, controller switch .9 is closed and the valves 2 and v are moved to the open position, that is, the position indicated for the brake-controlling mechanism V. The switch 8 is then moved to make contact with the contact 13, as a result of which the following circuit is closed: trolley T, wire, 25, wire 26, contact 12, switch 8, switch 8 contact 13, wire 31, train wire 7, wire 37, coil 38, wire 39, resistancer to ground. The momentary energization of this circuit by the operation of switch 3 causes the switch lever 55 to engage the contact 54, for which position the latch 58 is moved by the spring 57 to engage such lever andmaintain it in closed position. Then the controller C is moved from the position indicated so that the several contacts make contact with different ones of the contact blocks, as a result of which a circuit is estab-v lished as follows, if the controller is moved so as to bring contact block 0 into engagement with contact 1, which is the direction for forward motion of the motors: trolley T, Wire 25, wire 26, contact 12, switch .9, wire27, coil 33, wire 28, contact 8, contact block 0", contact block 0 contact 9, contact 3, contact block 0, contact block 0 contact 1, wire 29, contact 19, switch 8 wire 30, to train .wire 2, wire 40, coil 41, resistance r to ground. As a result of this circuit the core 43 is actuated and switch 46 is closed, establishing the following circuit through the motors: trolley T, wire '25, contact 52, switch 51, wire 53, contact 54, circuit breaker 55, coil 48, wire 47, armature winding'M, field winding f, switch 46, contact 45, resistance r armature winding M of a second motor, field winding f of such motor to ground. For this position of the controller C it will be understood the contact block 0 is moved out of contact with the contacts 4 and 5. The successive positions of the controller C result in varying the resistance r and the relation to each other of the-motors M, M, in a manner well known in the art but forming no part of this invention.

In the event that the controller C is moved in the opposite direction for the purpose of reversing, similar circuits are closed to those traced above through this controller by which an identical operation of the motorcontrolling mechanism is effected. The

switch 8 is adapted to release the circuit breaker 55 for which condition the spring 56 opens connection between this lever and the contact 54.- through the controller it will be apparent that if the switch 8 were not in a position shown in connection with the .brake operating mechanism V it would be impossible to operate the solenoid 41 and therefore to close the motor circuit, and since the handles of the valves 1) and o interlock, it is necessary that both of these valves be in the open position. as shown, in order to close switch 8 and thereby render the circuit closed by the controller effective. All of the controllers are shown in the neutral position, and if for the condition of the valves 0 and 12 shown in From the circuit above traced.

contact 19, wire 29, contact 5, contact block 8, contact 4, wire 32, to train wire 6. That is, the improper position of the switch 8 for the operation of the train from another location closes a path of low resistance between the train wires 2 and 6, which results in maintaining the energization of-the tripping coil 49 when any of the other controllers is moved to actuate the solenoid 41 to thereby close the motor circuit. From this it appears that it is necessary for the several valves 0 to all occupy the closed position indicated for the brake-operating mechanisms V, V and V in order to permit the operation under normal conditions of the motor mechanism of the train from the controller 0. The inability to operate the train from any one of the controllers is therefore a positive indication to the motor man that some of the air valves on the braking system are incorrectly set and that it is not safe to proceed under this condition. v

In my system Ialso provide means for preventing the operation of the train when the air pressure is insufficient for operating the brakes consisting in an air-operated switch connected with the supply pipe 10 such switch consistingin cylinder 20 adapted to contain a piston 21 normally held to the right by a spring 22, for which position a switch blade 17 makes contact with the contacts- 15 and 16, for which condition a circuit is closed between the train wires 2 and 6 as follows: train wire 2, wire 35, contact 16, switch 17, contact 15, wire 34, to train wire 6, and thus a low resistance path is closed between the train wires 2 and 6 with the same result produced by the other low resistance path just described. When the air pressure is sufficient to operate the brakes, however, the iston 21 is moved in the cylinder 20 to the l eft and the switch 17 is moved out of engagement with the contacts 15 and 16. p

In Figs. 2 and 3 a form-of construction of the switch 8 is indicated by which such switch may be readily attached to any of the well known types of valves used for controlling the brake mechanisms. The valve 12 located in ipe'p is provided with an operating hand e 60 in which is secured a screw 61 engaging by means of a slot the left hand end of a lever 62 pivotedat 64 to a supporting engaged from them when the handle 60 is moved to the vertical position. The base 65 is adapted to be supported from the pipe p by means of a bracket 66 and clip 67, as indicated.

The air-controlled switch above described may be adapted to be regulated for various pressures by means of a construction indicated in Fig. 4, in which the s ring 22 is held in position by a threaded p ug 68 screwed themselves to those skilled in the art.

What I claim as new and desire to secure by Letters Patent is:

1. In combination with a car ada ted to be electrically driven, two control ers on such car for operating the same, brakes carried by such car, mechanism associated with each of such controllers for controlling such brakes, and means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating position and the brake-controlling mechanism associated with the other controller is in a condition to prevent the application of the brakes from the operating controller.

2. In combination with a car ada ted to be electrically driven, two control ers on such car for operating the same, brakes carried by such car, mechanism associated with each of such controllers for controlling such brakes, and means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating position and the brake-controlling mechanism associated with the other controller is in an improper condition for the use of the operating controller.

3. In combination with a car ada ted to be electrically driven, two control ers on such car for o crating the same, air brakes carried by sucli car, a valve associated with each of such controllers 'for controlling such brakes, and means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating position and the valve associated such controllers for controlling such brakes, and means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating osition and the valve associated with the ot her controller is in an improper position for the use of the operating controller.

5. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes a switch associated with each of such valves, and means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating position and the switch associated with the other controller is in a proper position to operate the car from such other controller.

6. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes,

- means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating position and the valve associated with the other controller is in a osition to prevent the ap plication of the brakes from the operating controller, and means for openin such motor circuit consisting in a circuit adapted to be closed when the air pressure in such brake system is insufficient.

7. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating osition and the valve associated with the ot er controller is in an improper position for the no use of the operating controller, and means for opening such motor circuit consisting in a circuit adapted to ,be closed when the air pres sure in such brake system is insufficient.

8. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, a switch associated with each of such valves, means operated by one of such controllers for opening the motor circuit of such car when said controller is moved to an operating position and the switch associated with the other controller is in a proper position to operate the car from such other controller, and means for opening such motor circuit consisting in a circuit adapted to be closed when the air pressure in such brake system is insuflicient.

9. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating position and the valve associated withthe other controller is in a position toprevent the application of the brakes from the operating controller, and means for opening such motor circuit when the air pressure in the,braking system is insufficient consisting in switching mechanism operated by such air pressure and adapted to control such motor circuit-by the same means controlled by such valve.

10. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, ,a switch associated with each of such valves, means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an operating position and the switch associated with the other controller is in a pro er position to op- 1 eratethe car from such ot er controller, and

means for opening such motor circuit when the air pressure in the braking system is 1n- SllfIlClGIlt consisting in switch ng mechanism I operated by such air pressure and adapted to control such motor circuit by the same means controlled by such valve.

11. In combination with a car adapted to be electrically driven, two controllers on suchcar for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, a circuit breaker in circuit with such controllers for protecting the car motor or motors,

and means operated by one of such controllers for tripping such circuit breaker when such controller is moved to an operating position and the valve associated with the other controller is ina position to prevent the application of the brakes from the operating controller; l

12. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, a switch associated with each of such valves, a circuit breaker in circuit with such controllers for protecting the car motor or motors, and means operated by one of such controllers for tri ping such circuit breaker when such controller is moved to an o erating position and the switch associate with the other controller is in a pro er position to operate the car from such ot 1er controller.

13. In combination with a car adapted to car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, a circuit breaker in circuit with such controllers for protecting the car motor or motors,

means operated by one of such controllers for tripping such circuit breaker when such controller is moved to an operating position and the valve associated with the other controller is in a position to prevent the applica tion of the brakes from the operating controller, and means for opening such motor trollers for protectin' the car motor or motors, means operate by one of such con trollers for tripping such circuit breaker when such controller is moved to an operating position and the switch associated with the other controller is in a pro er position to operate the car from such other controller, and means for opening such motor circuit consisting in a circuit adapted to be closed when the air pressure in such brake system is insufiicient.

15. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of suchcontrollers for controlling such brakes, means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an o erating position and the valve associate with the other controller is in a osition to pre. vent the application of the akes from the operating controller, and means for opening such motor circuit when the valve associated with the operating controller is in an inoperative position.

16. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, a switch associated with each of such valves, means operated by one of such controllers for opening the motor circuit of such car when such controller is moved to an o erating position and the switch associate with the other controller is in a proper position to operate the car from such other controller, and means for opening such motor circuit when-the valve associated with the operating controller is in an inoperative position.

17. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried Cal by such car, a valve associated with each of such controllers for controlling such brakes, means operated by one of such controllers "for opening the motor circuit of such car when such controller is moved to an operating position and the valve associated with the other controller is in a position to prevent the application of the brakes from the operating controller, means for opening such motor circuit consisting in a circuit adapted to be closed when the air pressure in such brake system is insufficient, and means for opening such motor circuit when the valve associated with the operating controller is in an inoperative position.

18. In combination with a car adapted to be electrically driven, two controllers on such car for operating the same, air brakes carried by such car, a valve associated with each of such controllers for controlling such brakes, a switch associated with each of such valves, means operated by one of such controllers for opening the motor circuit of such car when said controller is moved to ano erating position and the switch associate with the other controller is in a proper position to operate the car from such other controller,

means for opening such motor circuit consisting in a circuit adapted to be closed when the air pressure in such brake system is in sufficient, and means for opening such motor circuit when the valve associated with the operating controller is in an inoperative position. v

19. In a system of train control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on one of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve on another of such cars for controlling the operation of such brakes, and means associated withsuch valve for opening such motor circuit when such valve is in an improper position for the operation of the train from such controller.

20. In a system oftrain control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on one of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve on another of such cars for controlling the operation of such brakes, a circuit breaker in circuit with such controller for protecting the motor or motors of such train, and means for tri ping such circuit breaker when such controller'is moved from its neutral position and the valve is in an im roper position for the operation of the train from such controller.

21. In a system of train control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on one of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve on another of such cars for controlling the operation of such brakes, a circuit breaker in circuit with such controller for protecting the motor or motors of such tram, a switch associated with such valve ada ted to close a circuit through such controller to trip the circuit breaker when such controller is moved from a neutral position and such valve is in an impro er position for the operation of the train roin such controller.

22. In a system of train control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on one of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve on another of such cars for controlling the operation of such brakes, a circuit breaker in circuit with such controller for protecting the motor or motors of such train, a switch associated with suth valve adapted to close a circuit through such controller to'trip the circuit breaker when such controller is moved from a neutral po sition and such valve is in an improper position for the operation of the train from such controller, and means for closing such tripping circuit when the air in such braking system is insuificient.

23,. In a system of train control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on each of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve associated with each of such controllers for controlling the operation of such brakes, and means associated with each valve for openingsuch motor'circuit when any of such valves is in an improper position for the operation of the train,

24. In a system of train control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on each of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve associated with each of such controllers for controlling the operation of such brakes, and means associated with each valve for closing a circuit through any one of such controllers when such controller is moved to operate the train and one of such valves on another partof the train is in an improper position, such circuit operating through such conductors to open the motor circuit of the train.

25. In a system of train control, a plurality of cars adapted to be electrically-driven, electric conductors extending through the train,

a controller on each of such cars adapted tocontrol the motor circuit of such train through such conductors, air brakes carried by such cars, a valve associated with each of such controllers for controlling theoperation of such brakes, a circuit breaker in circuit with the motor or motors of the train, a switch associated with each of such valves, and means for closing the tripping circuit of such circuit breaker through one of such switches and thereby opening the motor circuit of the train when the associated valve is in an improper position for the operation of the motor or motors from another part of the train.

26. In a system of train control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on each of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve associated with each of such controllers for controlling the operation of such brakes, a circuit breaker in circuit with the motor or motors of the train, a

switch associated with each of such valves, and means for closing the tripping circuit of such circuit breaker through one of such switches and thereby opening the motor circuit of the train when the associated valve is in an improper position for the operation of the motor or motors from another part of the train and when the controller there located is moved to a position ada ted to normally close the motor circuit of t e train.

27. In a system of train control, a plurality of .cars adapted to be electrically driven, electric conductors extending through the train, a controller on each of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve associated with each of such controllers for controlling the operation of such brakes, a circuit breaker in circuit with the motor or motors of the train, a switch associated with each of such valves,

anyone of such switches serving to close a low resistance path between two of such conductors when the associated, valve is in an improper position for the o 'eration of the motor or motors from anot or part of the train and to thereby operate the tripping circuit of such circuit breaker when a controller not associated with such switch is moved from its neutral osition.

28. In a system of train control, aplurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on each of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve associated with each of such controllers for controlling the operation of such brakes, a circuit breaker in circuit with the motor or motors of the train, a switch associated with each of such valves,

any one of such switches serving to close a low resistance path between two of such conductors when the associated valve is in an improper position for the operation of the motor or motors from another part of the train and to thereby operate the tripping circuit of such circuit breaker when a controller not associated with such switch is moved from its neutral position, and means for closing a similar low resistance path when the air pressure invthe braking system is insuificient.

29. In a system of train control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on each of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such cars, a valve associated with each of such controllers for controlling the operation of such brakes, a circuit breaker in circuit with the motor or motors of the train, a switch associated with each of such valves, any one of such switches serving to close a low resistance path between two of such conductors when the associated valve is in an improper position for the operation of the motor or motors from another part of the vtrain and to thereby operate the tripping circuit of such circuit breaker when a controller not associated with such switch is moved from its neutral position, switching mechanism associated with each controller and adapted to occupy an inoperative position unless manually held in operative position, and means for operating the train when suchlow resistance path is closed consisting in manually holding one of such switching mechanisms in operative position and operating the associated controller.

30. In a system of train control, a plurality of cars adapted to be electrically driven, electric conductors extending through the train, a controller on each of such cars adapted to control the motor circuit of such train through such conductors, air brakes carried by such'cars, a valve associated with each of such controllers for controlling the operation of such brakes, a circuit breaker in circuit with the motor or motors of the train, a

switch associated with each of such valves,

any one of such switches serving to close a low resistance path between two of such conductors when the associated valve is in an improper position for the operation of the motor or motors from another part of the train and to thereby operate the tripping circuit of such circuit breaker when a controller not associated with such switch is moved from its neutral position, switching mechanism associated with each controller and adapted to occupy an inoperative position unless manually held in operative position, means for operating the train when such low resistance path is closed consisting I In Witness whereof, I hereunto subscribe in manually holding one of such switching my name this twenty-fourth clay of Decemmechanisms in operative position and operather, A. D. 1907.

in the associated controller, and means for ADOLPH H. DAUS.

closing a similar low resistance path when l \(Vitnesses: the air pressure in the braking system is in- EDWIN T. MUNGER, sufficient. HARLEY A. JOHNSON. 

